More particularly, the invention concerns an ultrasound imaging method for imaging a field of observation in an environment to be imaged containing scatterers, said method comprising several successive measurement steps during each of which:                an array of transducers emits an incident ultrasound wave into the field of observation, of center wavelength λ,        then raw signals Sj(i,t) picked up by each transducer and representative of a reflected ultrasound wave reverberated from the incident wave by the scatterers in the environment are recorded, where i is an index denoting each transducer, j is an index denoting each measurement step, and t denotes the time,the array of transducers extending along at least one dimension and the incident waves mainly being propagated in a direction of propagation perpendicular to the array of transducers.        
In known methods of this type, the raw signals from different transducers are combined together for each shot, for example by beamforming, to obtain the images corresponding to each shot. The resolution of the image is normally limited to λ/2, where λ is the ultrasound wavelength (for ultrasounds at 1.5 MHz, λ is of the order of 1 mm in soft human tissue).
One particular objective of the present invention is to obtain an ultrasound image of a resolution better than λ/2.